diff --git a/src/util/timestamp.cc b/src/util/timestamp.cc
index 6486ec1..275cdd3 100644
--- a/src/util/timestamp.cc
+++ b/src/util/timestamp.cc
@@ -42,6 +42,7 @@
  #include <mach/mach_time.h>
 #elif HAVE_GETTIMEOFDAY
  #include <sys/time.h>
+ #include <stdio.h>
 #endif
 
 static uint64_t millis_cache = -1;